1. Field of the Invention
The present invention relates to an overhead image reading apparatus.
2. Description of the Related Art
An image reading apparatus including an image-capturing unit that images a medium to be read that is placed from above and a light source that irradiates the medium to be read with light with light has been known in related art. For example, Japanese Patent Application Laid-open No. 2001-28671 discloses a technology of an image reading apparatus including a stand block having a support arm, a scan type illumination means for applying a slit-shaped light beam onto a surface of a manuscript, and a manuscript image scanning means mounted on an upper part of the support arm for scanning a manuscript image illuminated by the slit-shaped light beam and reflected from the surface of the manuscript.
If brightness changes suddenly when the light source for irradiating a medium to be read placed thereon is turned on or off, the user may not be able to adapt himself/herself to the change in brightness and this may result in irritation to the user's eyes.